To store a liquid having fluidity such as a cosmetic liquid, a chemical, or a beverage, a resin container formed through injecting a molten resin over an outer surface of a hollow molded body (inner shell) made of a resin, thus overmolding a resin sheathing body (outer shell), has been proposed (see, for example, patent documents 1, 2 cited below). For such a resin container, different materials can be employed for each of the inner shell and the outer shell, which facilitates manufacturing a container suitable for the characteristic of the liquid to be stored therein, for example employing a corrosion resistant material for the inner shell and a mechanically strong material for the outer shell.
Now, for overmolding the resin sheathing body over the outer surface of the hollow molded body, it is necessary to minimize wobbling of the hollow molded body with respect to the molding die. Also, in the case where both of the hollow molded body and the resin sheathing body are of a square bottle shape, or respectively ornamented in a specific manner, the hollow molded body has to be oriented in a predetermined direction with respect to the molding die, in the overmolding process.
In this aspect, the resin molding method according to the foregoing documents 1 and 2 includes forming a screw thread on an open neck portion of the hollow molded body and the molding die in advance, and screwing them together thus fixing the hollow molded body to the molding die, before executing the overmolding.
[Patent Document 1]
International Publication No. 2008/010597 pamphlet
[Patent Document 2]
International Publication No. 2008/010600 pamphlet